Wall crane

ABSTRACT

The wall crane is used to raise a wall from a horizontal to a vertical position. The crane has a base, a telescopic post pivotally connected to the base and a pulley connected adjacent to the top of the post. A hook is used to connect the crane to the wall and a cable extends from the hook, over the pulley and terminates at a winch. By reeling the hook toward the winch, the wall is raised. A catch is connected to the post and engages the wall when it has been raised to a vertical position to prevent the wall from toppling over backward away from the crane.

[0001] This invention relates to equipment used in the construction ofhousing and more particularly to a hand-powered wall crane for raising apreformed wall to a vertical position.

[0002] The usual practice in the construction of the walls of a house isto assemble the frames for the walls on a level horizontal surface suchas a floor or the ground. The frame is then raised from the horizontalto vertical position and connected in place by wood braces, bolts or thelike. The frame is then prepared for wall boards such as dry wall panelsand finally the wall boards are attached to the frame.

[0003] The frames for walls are heavy, particularly when the frames arelong. It is conventional for a crew of men to raise the frames from thehorizontal to vertical positions. When the frame is vertical it isbraced to prevent it from toppling over.

[0004] I have invented a wall crane which does away with the need for acrew of men to raise a wall frame. The crane is powered by hand and canbe operated by one individual. The crane is portable and can beassembled by hand where needed and dismantled and removed, again byhand.

[0005] Briefly the wall crane of the invention serves to raise a wall toa vertical position comprising: a base having means by which the basecan be made stationary; a post pivotally connected to the base; a pulleyconnected to the post at a point spaced apart from the base, a hook forsecuring a wall; a winch; and a cable extending from the winch to thehook. The wall crane has stop means for selectively preventing pivotalmovement of the post relative to the base such that the post can be madeimmovable relative to the base. The wall crane further may have a catchconnected to the post for engaging the wall and preventing furtherraising thereof. In addition the post may be telescopic.

[0006] The wall crane of my invention is described with reference to theaccompanying drawings in which:

[0007]FIG. 1 is a perspective view of the wall crane in conjunction withthe frame of a wall resting on the ground;

[0008]FIG. 2 is a perspective view of the wall crane in enlarged scale;

[0009]FIG. 3 is a side view of the wall crane and a wall resting on theground;

[0010]FIG. 4 is a perspective view of the crane and the wall raised toan angle of about 45 degrees from the ground;

[0011]FIG. 5 is a perspective view of the crane and the wall raised to afully upright position.

[0012] Like reference characters refer to like parts throughout thedrawings.

[0013] With reference to FIG. 1, the wall crane, generally 10, comprisesa post 12 and a pulley 14 adjacent to the upper end of the post. A base16 is at the opposite end of the post. The crane is anchored to astationary floor 17 on which the frame of a wall 18 rests.

[0014] With reference to FIG. 2, the base has a bottom wall 20 and apair of side walls 22, 24 which extend normally upward from the bottomwall and which are disposed on opposite sides of post 12. A pair ofbraces 25 is provided for supporting each side wall.

[0015] The bottom wall has a number of apertures 26 formed in it forreceipt of nails so that the base an be anchored to floor 17 or to someother stationary object.

[0016] Side walls 22, 24 are connected to the post by two bolts; a lowerbolt 28 and an upper bolt 30. Both bolts pass through apertures formedin the plates and the post. The apertures in the post are larger thanthe cross sectional area of the lower bolt so that the post may pivotrelative to the walls. The upper bolt 30 is held in place by means ofnut 31. Other means may also be used for maintaining the bolt in placesuch as a cotter pin. Whatever means is used, it must allow the upperbolt to be removed easily so that the post can pivot relative to thebase when that is required.

[0017] Upper bolt 30 serves as a stop means for selectively preventingpivotal movement of the post relative to the base such that the post canbe made immovable relative to the base.

[0018] A hook 32 is located on the side of the post opposite the bottomwall. The hook has a lower face 34 and inner faces 36 and an outer lip38 bent back at right angles from the lower wall. The lower face issufficiently wide to receive the top plate of a wall as described below.An aperture 39 is formed in the lip for receipt of a nail for a purposeto be described below.

[0019] A crampon 40 is connected to the upper end of the inner face andserves to connect the hook to cable 41. The cable extends along thelength of the post to its upper end, around pulley 14 and terminates ata winch 42 on the opposite side of the post.

[0020] The upper end of the post is bifurcated into two branches 12 a, band the pulley is mounted for rotation in bearings in the two branches.The two branches terminate above the pulley and a retaining rod 43extends between the two branches and adjacent to the upper edge of thepulley. The retaining rod has an enlarged head (not illustrated) at oneend and a cotter pin 44 at the other end to ensure that it remainsconnected to the post. The rod may however be removed from the post byremoving the cotter pin, from the retaining rod.

[0021] The retaining rod ensures that the cable remains in the groove ofthe pulley when the wall crane is in use. When the crane is beingstored, the rod may be removed so that the cable can be removed from thepulley.

[0022] The winch is of conventional construction and is mounted to thepost on the side opposite the clasp. The winch has a handle 45 (FIG. 1)for winding and unwinding the cable. Winding the winch causes the hookto move along the post toward the pulley and unwinding the winch causesthe hook to move in the opposite direction and to resume the positionillustrated in FIG. 2.

[0023] The post is hollow and is composed of two segments, a lowersegment 12 c and an upper segment 12 d. Preferably the segments are ofequal length. The latter segment has a smaller cross-sectional area thanthe former so that it fits into the lower segment. A conventionalconnecting pin 50 fits though apertures in the two segments tointerconnect them and a cotter pin (not illustrated) is provided toprevent removal of the connecting pin rom the apertures unless thecotter pin is removed.

[0024] The post is thus telescopic in the sense that it can belengthened or shortened. A number of apertures 51 through which theconnecting pin may be inserted can be formed in the upper segment toallow for adjustability in the length of the post. The post canaccordingly be adjusted to the height of the wall which the wall craneis used to raise.

[0025] A catch 52 is connected to the upper segment 12 d of the post.With reference to FIGS. 3 and 4, the catch has a pair of interconnectedinner and outer arms 52 a,b. Inner arm 52 a extends outwardly from thepost and terminates at the outer arm 52 b. The purpose of the catch isdescribed below.

[0026] The operation of the wall crane is described with reference toFIGS. 1 and 3 to 5. With reference first to FIG. 1, two wall cranes aremounted beside the top plate 64 of the frame of a previously constructedwall or partition. The bottom wall 20 of the base of each wall crane isanchored to floor 17 so that the bottom walls are stationary.

[0027] The hook of each wall crane is then attached to the top plate andis held in position be means of nails driven through apertures 39 in theouter lip of each hook. The hooks are then raised by means of thewinches of each crane. As the hooks rise the wall pivots upwardly aboutits lower plate 70.

[0028] With reference to FIG. 4, as the wall pivots, the top plate moveshorizontally away from the wall crane in the direction of arrow 69. Theupper bolt 30 which connects the base to the post of each crane is thenremoved to allow the post to pivot forward to accommodate this movement.

[0029] With reference to FIG. 5, when the wall is vertical, the innerarm 52 a of the catch is above the wall and outer arm 52 b is in contactwith the upper edge of the wall. The catch prevents the wall frompivoting past the vertical. In the absence of the catch, the wall mightpivot past that point and if it did, the wall would topple over in theopposite direction. The wall crane is not capable of preventing that inthe absence of the catch.

[0030] To ensure that the catch is in the correct position the height ofthe wall is measured while it is resting on the floor and before it islifted by the wall crane. The effective length of the post is adjustedby means of connecting pin 50 so that the catch will be in the requiredposition when the wall is upright.

[0031] Once the wall is vertical it is braced by conventional means toprevent it from moving. The hook is then raised by the winch to removeit from contact with the wall and the post is swung back to the verticalposition and out of contact with the wall.

[0032] The angle between the outer arm 52 b of the catch and the outerface 66 a of the wall, marked 80 in FIG. 5, should be in the range ofabout 45 degrees to 60 degrees, preferably 50 degrees. If the angle isless than that, the weight of the wall against the catch will make itdifficult to disengage the wall from the catch even though the wall isvertical. If the angle is more than about 60 degrees, the catch may notbe effective to firmly contact the wall to prevent the wall fromtoppling over backward.

[0033] It will be understood of course that modifications can be made inthe structure of the wall crane illustrated and described herein withoutdeparting from the scope and purview of the invention.

I claim:
 1. A hand-powered wall crane for raising a wall to a verticalposition comprising: a base having means by which said base can be madestationary; a post pivotally connected to said base; a pulley connectedto said post at a point spaced apart from said base; a hook for securingthe wall; a cable extending from said winch, over said pulley and tosaid hook; and a winch for winding and unwinding said cable.
 2. The wallcrane as claimed in claim 1 further including stop means for selectivelypreventing pivotal movement of said post relative to said base such thatsaid post can be made immovable relative to said base.
 3. The wall craneas claimed in claim 1 further including a catch connected to said postfor engaging said wall when in a vertical position and preventingfurther pivoting of said wall past said position.
 4. The wall crane asclaimed in claim 1 wherein said post is telescopic.
 5. The wall crane asclaimed in claim 1 further including means for preventing said cablefrom separating from said pulley.
 6. The wall crane as claimed in claim1 wherein said post extends from said base and terminates at an upperend, said upper end being bifurcated into two spaced apart branches,said pulley being rotatably disposed between said branches, said wallcrane further including a retaining rod extending between said branchesadjacent to said upper and preventing said cable from separating fromsaid pulley.
 7. The wall crane as claimed in claim 6 wherein saidretaining rod is separable from said branches to permit removal of saidcable from said pulley.
 8. The wall crane as claimed in claim 3 whereinsaid catch has a pair of interconnected inner and outer arms, said innerarm extending outwardly from said post and terminating at said outerarm, said inner arm being disposed above said wall and said outer armbeing disposed at an angle in the range of about 45 degrees to 60degrees from said wall when said wall is in a vertical position.
 9. Thewall crane as claimed in claim 8 wherein said angle is about 50 degrees.10. A hand-powered wall crane for raising a wall to a vertical positioncomprising: a base having means by which said base can be madestationary, a post pivotally connected to said base; a pulley connectedto said post at a point spaced apart from said base; a hook for securingthe wall; a cable extending from said winch, over said pulley and tosaid hook; a winch for winding and unwinding said cable; stop means forselectively preventing pivotal movement of said post relative to saidbase such that said post can be made immovable relative to said base;and a catch connected to said post for engaging said wall when in avertical position and preventing further pivoting of said wall past saidposition.
 11. The wall crane as claimed in claim 10 wherein said post istelescopic.
 12. The wall crane as claimed in claim 10 further includingmeans for preventing said cable from separating from said pulley. 13.The wall crane as claimed in claim 10 wherein said post extends fromsaid base and terminates at an upper end, said upper end beingbifurcated into two spaced apart branches, said pulley being rotatablydisposed between said branches, said wall crane further including aretaining rod extending between said branches adjacent to said upper endand preventing said cable from separating from said pulley.
 14. The wallcrane as claimed in claim 13 wherein said retaining rod is separablefrom said branches to permit removal of said cable from said pulley. 15.The wall crane as claimed in claim 10 wherein said catch has a pair ofinterconnected inner and outer arms, said inner arm extending outwardlyfrom said post and terminating at said outer arm, said inner arm beingdisposed above said wall and said outer arm being disposed at an anglein the range of about 45 degrees to 60 degrees from said wall